Process of separating tungsten compounds from substances.



UNITED STATES PATENT oEEIoE.

CARL ANDERSEN AND ERIC HJ'ALMAR WESTLING, OF SAN FRANCISCO, CALIFORNIA.

PROCESS OF SEPARATING- TUNGSTEN COMPOUNDS FROM SUBSTANCES.

No Drawing.

To all whom it may concern:

Be it known that We, CARL ANDERSEN, a subject of Denmark, and ERIC HJALMAR WESTLING, a citizen of the United States, both residents of the city and county of San Francisco, State of California, have invented a certain new and useful Process of Separating Tungsten Compounds from Substances, of which the following is a specification.

The invention relates to a fprocess of separating tungsten compounds rom substances and more particularly, to a process of separating tungsten compounds from tungstic acid solutions,

An object of the invention is to provide a process of producing substantially pure tungsten compounds.

Another object of the invention is to provide a process for separating tungsten compounds from an alkaline solution of tungstic acid.

The preferred method of carrying out the process of our invention will be set forth at length in the following description, but it is to be understood that variations in the process may be made without departing from the invention as expressed in the claims.

The process consists in treating an alkaline solution of a tungstate with a salt of a trivalent metal, preferably a ferric or an aluminum salt. If the tungsten is present as ammonium tungstate, sodium tungstate Specification of Letters Patent.

Patented Jan. 28,1919.

Application filed April 30, 1917. Serial No. 165,496.

or other alkaline metal or soluble tungstate, a ferric, aluminum or other trivalent salt such as ferric sulfate and an alkali earth hydroXid are added to the solution, and the tungstate of the trivalent metal, such as ferric tungstate, is precipitated. The precipitate is separated from the solution by filtration and washed with Water.

The main reaction occurs substantially according to the following equation:

We claim:

1. The process of separating tungsten compounds from solutions containing tungsten, which consists in adding a salt of a trivalent metal and an alkali metal hydroXid to the solution .whereby a tungstate of the trivalent metal is precipitated.

2. The process of separating tungsten compounds from solutions containing tungsten, which consists in adding a ferric salt and an alkali metal hydroxid to the solution whereby ferric tungstate is precipitated.

In testimony whereof We have hereunto set our hands at San Francisco, California, this Qelth day of April, 1917.

CARL ANDERSEN. ERIC HJALMAR WESTLING.

In presence of H. G. PRosT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). C. 

